Method of making blanks for coining



May 5, 1964 METHOD OF MAKING BLANKS FOR COINING Filed Dec. 6, 1960 PRIOR ART METAL COIN BLANK 4 Sheets-Sheet 1 v FIG. 2 PRESENT INVENTION SCRAP LOSS METAL IN LINE 20% I m M X MUM CHIPPING COIN FETTLING BLANK HOT ROLLING I SHEARING ANNEALING g g DRESIS'NG 25%TO30% COLD ROLLING I SHEARING ENDN TRIMMI e- SCRAP L083 30% PHILIP G.TURNER INVENTOR QQMQ ATTORNEY y 1954 P. G. TURNER METHOD OF MAKING BLANKS FOR comma 4 Sheets-Sheet 2 Filed Dec. 6, 1960 PHILIP G.TURNER ATTORNEY y 5, 1964 P. G. TURNER 3,131,472

METHOD OF MAKING BLANKS FOR COINING Filed Dec. 6, 1960 4 Sheets-Sheet 3 FIG. 5

FIG.6

34 FIG. 7 v 36 PHILIP G.TURNER INVENTOR ATTORN E Y y 1964 P. G. TURNER 3,131,472

' METHOD OF MAKING BLANKS FOR comma Filed Dec. 6, 1960 4 Sheets-Sheet 4 FIG. 8

PHILIP G.TURNER INVENTOR BY (1- (AM ATTORNEY United States Patent l 3,131,472 METHQD Gi MAKING BLANKS FOR (JOINING Philip George Turner, lnkberrow, England, assignor to Ihe international Nickel Company, Inc, New York, N.Y., a corporation of Deiaware Filed Dec. 6, 1960, Ser. No. 74,037 N Claims priority, application Great Britain Dec. 14, 19:19 2 Claims. (Cl. 29528) The present invention relates to the production of coins, tokens, medallions, medals, etc, and, more particularly, to the production of these disc-like structures from metallic nickel.

It is well known that for hundreds of years coins have been made by punching circular or polygonal blanks accurately to size from metal strip of the desired thickness and ressing the blanks between coining dies to produce a desigi in relief on the faces of the blank. The process of making clean strip to very close tolerances of thickness in the tough metals and alloys used for coinage is complex and expensive and the residue from the punching operation is expensive scrap which can only be used for remelting. The complexity of the operations and the extent of the losses involved can be seen from the following description of the manufacture of nickel coins.

The manufacture of high quality of nickel strip for coining is illustrated in FIGURE 1 and involves first of all the steps of melting the nickel, casting it into ingots of square section, cutting off the heads of the ingots and planing their sides to square section. These operations result in a scrap loss of some 27%. From the planed ingot, a hot rolled strip bar is produced which is then chipped and tettled and subsequently hot rolled again to strip 6-8 inches wide and approximately one-eighth inch in thickness. The strip is then sheared, annealed, dressed and cold rolled very accurately to the thickness required for the coin. The strip is again sheared to the multiple width required by the coin diameter and end trimmed. All these operations result in a further scrap loss of the order of 25%30% and in punching the coin blanks from the resulting strip, further scrap loss of some 30% is incurred. The overall conversion of virgin metal to finished coins is only about 35%. While the aforementioned scrap data show only a total conversion of about 35% of virgin metal to coin, these data do not accurately re fleet the monetary losses involved. Thus, when scrap is formed at any given stage of a process, this scrap reflects not only the costs of rernelting and repu-rifying the metal thus scrapped, but also involves the non-recoverable loss of the very high labor charges involved in the production of the product to the point at which the scrap is formed. Thus, the 30% scrap loss occurring during punching the blanks involves a production cost of about $0.51 per pound of scrapped nickel including about $0.08 per pound of nickel for ingot preparation, about $0.06 per pound of nickel for hot rolling, about $0.08 per pound of nickel for cold rolling and about $0.28 per pound of nickelior shearing and trimming, etc. Although many attempts were made to substantially reduce the costs and other difiicult-ies involved in present day coining practice, none, as far as I am aware, was entirely successful when carried into practice commercially on a modern industrial scale. 0

It has now been discovered that by means of a specially correlated combination of processing operations, blanks for coins, medals, etc., can be made from nickel in an expeditious and inexpensive manner.

It is an object of the present invention to provide a novel process for producing blanks tor nickel coins, nickel medals, nickel medallions, etc.

Another object of the invention is to provide a novel,

3,131,472 Patented ll/lay 5, 19.64

inexpensive process for producing said blanks which process is particularly adapted tor high speed operation.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawing in which:

FIGURE 1 is .a diagram illustrating the prior art sequence of operations employed in the current production of coin blanks;

FIG. 2 depicts rdiagrannnatically the sequence of process operations contemplated by the present invention;

FIG. 3 shows an apparatus in accordance with the present invention employed to segregate proper sized nickel pellets;

FIG. 4 shows another suitable segregation apparatus;

FIG. 5 illustrates a die tor working nickel pellets;

FIG. 6 depicts a shearing apparatus for trimming oversized blanks;

FIG. 7 shows a closed die stamping apparatus which can be employed in accordance with the present invention; and

FIG. 8 is a reproduction of a photograph of a section of a nickel pellet particularly adapted to be employed in the present process.

Generally speaking, the present invention contemplates forming a circular or substantially circular-like, e.g., polygonal, coin blank or disc by stamping a ductile pellet of carbonyl nickel of weight at least equal to that of the desired blank between dies to the desired thickness and then if necessary clipping the stamping to the desired shape. By clipping is meant the operation of punching out the shape from the stamping by means of an appropriately shaped punch and complementary die. Any scrap resulting irom the production of blanks in this way has not attracted heavy process costs and it has not been contaminated by repeated processing and, thus, decreased value. Afiter annealing, the blank can be coined in the usual way. The advanatges of the novel process of the present invention are illustrated in FIGURES 1 and 2 of the drawing. From these figures, it is to be observed that in the process of the present invention only two operations are required to produce a coin blank whereas in current mint practice more than 11 operations are required.

.To reduce wastage on clipping, the sectional shape of the initial piece of metal or alloy in the plane of the die faces is related to that of the blank to be formed, so that uniform spreading in the plane of the die faces on stamping gives a stamping of substantially the desired shape and size. The weight of the piece is so chosen that there is a relatively small amount of excess metal to be removed from the edges of the stamping. It is convenient to allow 5% to 10% overweight.

The present invention is particularly directed to the manufacture of nickel coin blanks, i.e., coin blanks made from substantially pure nickel metal and, accordingly, an important feature of the invention is the production of a substantially carbon-free nickel pellet by the process described in British patent specification No. .620,- 287. As described in the British patent specification, nickel pellets are preheated and caused to flow-in coun tercurrent to gas containing nickel carbonyl, the initial composition of the carbonyl, the rate of flow of the gas and the initial temperature of the pellets being correlated to eliminate carbon deposition wholly or substantially Wholly. The small starting pellets should, of course, themselves be substantially carbon free. The resulting pellets are of high purity, substantially spherical shape and uniform internal structure and do not exhibit the onion skin structure characteristic of pellets made by earlier processes. On stamping, they undergo uniform radial distortion in the plane of the die faces to substantially circular stampings from which circular blanks can be clipped. Specifically, a pellet which, for

coinage usage, should have a diameter controlled to give a weight corresponding to the weight of the final coin required plus up to about 20% of that weight, is made by providing a seed pellet, preheating this pellet to a temperature below about 200 C. and moving the seed pellet in conjunction with other pellets countercurrent to a how of gas containing controlled amounts of gaseous nickel carbonyl (i.e., Ni(CO) at such a rate that as the pellet cools it is subjected to an increased concentration of nickel carbonyl. When the temperature of the pellet falls below that temperature required to maintain the carbonyl decomposition reaction under the conditions employed, it is recycled through the heating and decomposition stages. By means of this process, pellets suitable for coinage usage can readily be produced.

When the pellets have been produced, they are accurately segregated by means of a sizing or weighing apparatus which operates selectively. A suitable sizing apparatus is shown in FIG. 3. Referring now thereto, it is to be observed that pellets 11 roll (advantageously by force or gravity) down fixed sloping rails 12. Rails 12. in addition to being fixed in sloping relationship are also fixed in diverging relationship to define a slot 13 therebetween, which slot 13 is wider at the bottom end of the rails than at the top. When a pellet of the proper size to be employed in manufacturing coins according to the method of the present invention passes position 14 on the rails, it Will fall through slot 13 into pellet collector 16. Position 15 on rails 12 indicates the farthest location of the opening for pellet collector 16 in order that the pellet collector will collect only those substantially spherical pellets which are within the tolerances required for a given coin. Pellets which are too small for use in the manufacture of a specific coin will fall through slot 13 before they pass position 14 and thus, not be collected in pellet collector 16. These small pellets can be recycled through the pellet forming process described hereinbefore and thereafter sized again. On the other hand, any pellets which are too large for use in the manufacture of a given coin will fall through slot 13 after passing position 15. These pellets can advantageously be employed in other uses for metallic nickel but ordinarily, while possible, it is not economically advantageous to attempt to reduce the size of the pellets so that they can be employed for the manufacture of a given coin. Alternative means of sizing are shown in FIGURE 4 wherein pellet 11 is rolled down incline plane 17 over edge 18. After passing edge 18, the pellet is subject to a magnetic field advantageously produced by means of a direct current electromagnet 19 energized through circuit 20 by direct current source 2i. Pellet collector 16 is positioned so that those pellets which are smaller or larger than required will fall to either side of the collector and those pellets which are of the proper size will be collected within pellet collector 16.

After the pellets are selected as being proper size for a given coin, they are subjected to a stamping operation in an apparatus such as illustrated in FIG. 5. Referring now thereto, it is to be observed that the stamping apparatus comprises top tool 22 and bottom tool 23 which 'tools are positioned in a stamping press of a type well known to those skilled in the art and not otherwise illustrated here. Bottom tool 23 contains a dish-like depression 24- on its upper surface 25 which for the manufacture of most coins has a substantially circular perimeter. The lower face 26 of top tool 22 (which lower face is adapted to abut against the top face 25 of bottom tool 23) contains a depression 27 which is substantially larger in diameter than depression 24. The volume enclosed within the diameter of depression 24 and the surface of tools 22 and 23 is substantially equal in volume to the desired coin. In operation the tools are axially parted. A pellet is inserted in depression 24. Axial pressure is then applied to the tools to force them together and as shown in the drawing in section, coin blank 28 is formed between said tools. This coin blank can and usually does have a small amount of flash 29 which extends into that free volume not within the perimeter of depression 24. Oversize blanks are then subjected to a clipping operation which can be performed in an apparatus such as shown in FIG. 6. Referring now thereto, it is to be noted that coiri blank 23 is inserted into die 30 in such fashion that flash 29 extends radially outward from die face 33. Die 36 is rigidly supported on die support 31. Punch 32, movable in a direction normal to the plane defining the circular cross section of coin blank 28 as it is positioned in die 39, is mounted coaxially with said die 30 and is proportioned so that its fits closely within die face 33. Pressure applied to punch 32, moving said punch in the direction as indicated by the arrow, results in flash 29 being clipped from coin blank 28.

If the metal is unconfined during the stamping operation, the stamping may be thinner at the edges than at the center and, advantageously, one or both of the dies can be provided with a rim or means having a rim-like function such as depression perimeter 24a as shown in FIG. 5 to limit the spreading of the metal and ensure that the desired thickness is attained over as large an area as possible. The stamping can be performed cold, or if necessary, hot. Advantageously, the stamping is completed in a single operation.

If the piece of metal used has the same weight as the desired blank, the dies should be closed at the edges and the blank is then formed directly in one stage by precision stamping between closed dies without the need for a clipping operation. Suitable apparatus is illustrated in the drawing at FIG. 7. Referring now thereto, it is to be observed that the closed dies comprise top tool 34, bottom tool 35 having abutable faces 36 defining closed cavity 37 in which after stamping coin blank 28 is formed. It is also contemplated that ejection means of types well known to those skilled in the art can be employed to remove blank 28 from cavity 37 after tools 34 and 35 have been parted. For the purpose of giving those skilled in the art a better understanding of the invention and/or a better appreciation of the advantages of the invention, the following illustrative example is given:

Example In the manufacture of a coin such as a 2 Shilling piece, the blank is produced by hot stamping a substantially spherical, ductile, carbonyl nickel pellet weighing about 14 grams (slightly larger than 14 mm. in diameter) to form a disc 1.2 inch in diameter and 0.085 inch thick. This disc is then clipped to form the finished blank which has the same thickness but which has a diameter of 1.11 inch. By working in this manner, the blank can be produced for a factory cost which is about 37% lower than the factory cost of conventional processing, said costs being exclusive of the cost of the metal employed.

An enlarged photographic reproduction of the structure of a carbonyl nickel pellet is shown in FIGURE 8. Referring now thereto, it is to be observed that a carbonyl nickel pellet as depicted therein and as employed in the foregoing example is characterized by a uniform structure and by freedom from gross, annularly disposed layers of carbon which were evident in pellets made by methods employed heretofore. Such annularly disposed layers of carbon in prior pellets made such prior nickel pellets substantially non-ductile and thus, not adapted to be employed in the present novel process.

The present invention is particularly applicable to the manufacture of blanks having a radial dimension substantially greater than the thickness to be used for coins, medals, medallions and other disc and disc-like structures which must be made of nickel.

Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims.

I claim:

1. A process for the production of disc-like metal objects having a radial dimension substantially in excess of the thickness and uniquely suited to be coined while avoiding the expensive scrap-producing steps involved in the production of rolled metallic sheets and discs therefrom which comprises producing a plurality of substantially carbon-free, ductile nickel pellets by preheating nickel-seed pellets and causing deposition of nickel to occur thereon by flowing said seed pellets in countercurrent to a nickel carbonyl-containing gas at a temperature below about 200 (3., segregating from the thusproduced ductile carbon-free pellets selected pellets at least equal in volume to but not substantially exceeding the volume of the desired discs, stamping said selected pellets to produce a plurality of thin discs and clipping any excess metal from said thin discs to provide blanks adapted to be coined to final configuration whereby said blanks are obtained from a readily producible inex pensive shape.

2. A process for the production of disc-like metal objects having a radial dimension substantially in excess of the thickness and uniquely suited to be coined while avoiding the expensive scrap-producing steps involved in the production of rolled metallic sheet and discs therefrom which comprises providing a plurality of substantially carbon-free, ductile nickel pellets made by preheating nickel-seed pellets and causing deposition of nickel to occur thereon by flowing said seed pellets in countercurrent to a nickel carbonyl-containing gas at a temperature below about 206 C., segregating from said pellets selected pellets at least equal in volume to but not substantially exceeding the volume of the desired discs, stamping said selected pellets to produce a plurality of thin discs and clipping any excess metal from said thin discs to provide blanks adapted to be coined to final configuration whereby said blanks are obtained from a readily producible inexpensive shape.

References Cited in the file of this patent UNITED STATES PATENTS 1,617,161 Koref et al Feb. 8, 1927 2,057,669 Brauchler Oct. 20, 1936 FOREIGN PATENTS 620,287 reat Britain Mar. 22, 1949 

1. A PROCESS FOR THE PRODUCTION OF DISC-LIKE METAL OBJECTS HAVING A RADIAL DIMENSION SUBSTANTIALLY IN EXCESS OF THE THICKNESS AND UNIQUELY SUITED TO BE COINED WHILE AVOIDING THE EXPENSIVE SCRAP-PRODUCING STEPS INVOLVED IN THE PRODUCTION OF ROLLED METALLIC SHEETS AND DISCS THEREFROM WHICH COMPRISES PRODUCING A PLURALITY OF SUBSTANTIALLY CARBON-FREE, DUCTILE NICKEL PELLETS BY PREHEATING NICKEL-SEED PELLETS AND CAUSING DEPOSITION OF NICKEL TO OCCUR THEREON BY FLOWING SAID SEED PELLETS IN COUNTERCURRENT TO A NICKEL CARBONYL-CONTAINING GAS AT A TEMPERATURE BELOW ABOUT 200* C., SEGREGATING FROM THE THUSPRODUCED DUCTILE CARBON-FREE PELLETS SELECTED PELLETS AT LEAST EQUAL IN VOLUME TO BUT NOT SUBSTANTIALLY EXCEEDING THE VOLUME OF THE DESIRED DISCS, STAMPING SAID SELECTED PELLETS TO PRODUCE A PLURALITY OF THIN DISCS AND CLIPPING ANY EXCESS METAL FROM SAID THIN DISCS TO PROVIDE BLANKS ADAPTED TO BE COINED TO FINAL CONFIGURATION WHEREBY SAID BLANKS ARE OBTAINED FROM A READILY PRODUCIBLE INEXPENSIVE SHAPE. 